Bargain-hunting shoppers turned the latest Cyber Monday into the biggest e-commerce day in history, according to data from IBM Digital Analytics Benchmark.

Online sales surged 20.6% compared with last year's Monday after Thanksgiving. Los Angeles was the third most active e-shopping city after New York and Washington but ahead of Chicago and Atlanta, IBM said.

Cyber Monday capped the highest five-day online consumption period in the books, as sales jumped 16.5% over the same stretch last year. That's even though the average order on Cyber Monday sank 1% to $128.77 from a year earlier, dropping below the $135.27 average transaction on Black Friday.

"You're seeing more and more consumers shopping online instead of going to bricks-and-mortar retailers," said Brian Yarbrough, an analyst with Edward Jones. "People are under the impression that the Internet has cheaper prices and is more convenient, allowing you to avoid the crowds.

"Honestly, I think Black Friday in the future will probably lessen in importance to the overall holiday shopping season."

Digital data firm ComScore Inc. found that Cyber Monday shopping via desktop computers soared 18% from a year earlier to $1.74 billion. After Black Friday's $1.2-billion online spending spree, it was the second day of the season to surpass $1 billion in sales, according to the firm.

Visa Inc. reported that e-commerce sales from its account holders increased 30% year over year to $7.8 billion from Thursday through Monday. Spending on U.S. Visa cards totaled $2.6 billion on Cyber Monday, a 28% boost from 2012.

Deal site Groupon Inc. said Black Friday and Cyber Monday were its two most successful days ever in North America. Top sellers included toys — 47,000 Royal Loom Bands kits were sold — as well as home goods, including 15,000 Keurig Vue V500 Brewing Systems.

Wal-Mart Stores Inc. said Cyber Monday was the biggest online sales day in its history. The retailer said its website processed more than 1 billion page views from Thursday through Monday, with top sellers including a 50-inch LG LED HDTV and a Wi-Fi-equipped Apple iPad 2.

But as a whole, retailers' performance over the holiday weekend was unimpressive.

Research firm ShopperTrak said sales in stores over the four-day period were up 1% to $22.2 billion as foot traffic sank 4% to 1.8 billion visits.

Although visits to apparel stores were up 9.4% year over year, electronics retailers suffered a 6.5% drop, according to ShopperTrak. Many consumers went online to research products before heading into stores with clear goals.

"Mixed shopping reports suggesting just moderate spending" helped push the Dow down nearly 78 points Monday, its worst day since Nov. 7, according to a note to clients from Sterne Agee chief economist Lindsey Piegza.

In hopes of attracting more shoppers over more days, many chains spread out their bargains and promotions from Thursday through Cyber Monday, if not longer.

"Retailers stretched Black Friday deals and promotions across November — removing the focus from just one big day of shopping," ShopperTrak founder Bill Martin said. "Shoppers, in turn, paced themselves."

Jefferies analyst Brian Pitz pointed to other concerns: the fact that the period between Thanksgiving and Christmas is the shortest it's been in more than a decade along with "recent weakness in discretionary spending."

The International Council of Shopping Centers said that sales were soft but that purchasing early in the holiday season is "no bellwether of the season as a whole."

"Consumers have completed an average 37.3% of their holiday gift buying, which means there is still a lot to do over the upcoming weeks," Michael Niemira, chief economist of the trade group, said in a statement.

Yarbrough, the analyst, said that shopping probably will kick up in the two weeks before Christmas.

"The first week of December is usually a lull period," he said. "People are really burnt out from Black Friday."